Timing = function(options){
	var _options = {};
	$.extend(_options,this._options,options);
	$.extend(this,{   
		_options:_options
	});
	this._init();
};
$.extend(Timing.prototype,Timer.prototype,{
	_options:{
		maxms:0,
		minms:0,
		callback:null
	},
	_diffms:0,
	_init:function(){
		this._diffms = this._options.maxms-this._options.minms;
	},
	_onTick:function(){
		this._diffms = this._diffms-this._during;
		var remain = Utils.date.diff(this._diffms);
		this._options.callback(remain,this);
	}
});